JP2010076278A - Ejector of injection molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce work load of exchanging an ejector rod and also to reduce a time and cost for exchanging the ejector rod when exchanging a mold in an injection molding apparatus by detachably fixing a part of or all of respective ejector rods to an ejector plate by magnetism in an ejector of the injection molding apparatus. <P>SOLUTION: A plurality of rod insertion holes 10 are penetratedly formed in a movable platen 3, the plurality of ejector rods 11 are slidably inserted into all of the rod insertion holes 10, and an ejector plate 12 is disposed on the rear face of the movable platen 3. In the ejector rods 11, a plurality of base rods 15 are slidably inserted into all of the rod insertion holes 10, and a base end part is fixed to the ejector plate 12. An attaching/detaching rod 16 is detachably attracted to each base rod 15 by the magnetism of the first and second magnets 20, 21. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ejector device of an injection molding machine, and particularly includes a magnet type rod fixing means for generating a magnetic force for removably fixing a part or all of each ejector rod to an ejector plate.

  Conventionally, in an injection molding machine, a mold (a fixed mold and a movable mold) is attached to a fixed platen and a movable platen, and the movable platen is driven in a direction toward and away from the fixed platen to close the mold. Mold opening is performed. Molten synthetic resin is supplied to the cavity in the closed mold, and the molten synthetic resin is cured to form a molded product. After the mold is opened, the molded product is molded by the ejector device. Ejected from.

  In an ejector device of an injection molding machine, an ejector plate is disposed on the back side of a movable platen, and one or a plurality of ejector pins (ejector rods) are slidably inserted into the movable platen, and a base end portion of the ejector pin is It is fixed to the ejector plate. When the ejector plate is driven in a direction approaching / separating from the platen, the ejector pin is driven forward and backward over the eject position where the ejector pin has advanced and the standby position where it has retracted.

  The ejector pin is configured as one continuous integrated pin, and as a structure for fixing the base end portion of the ejector pin to the ejector plate, the ejector pin is passed through the ejector plate, and the ejector plate is inserted into the retainer plate from the back side. Are fastened with a plurality of bolts, and the ejector pin and retainer plate sandwich the base end flange of the ejector pin (see, for example, Patent Document 1), or the base end of the ejector pin is screwed to the ejector plate. Such a structure (for example, see Patent Document 2) is known.

  In the ejector device of an injection molding machine described in Patent Document 3, an air cylinder is fixed to an ejector plate toward a platen, and a base end flange portion of an ejector pin is connected to the cylinder rod via a joint. The base end flange portion of the ejector pin is engaged with the concave portion of the joint so as to be disengageable from the direction orthogonal to the axis, and is fixed in a state of being prevented from rotating with a bolt. The ejector pin can be replaced by removing this bolt.

  In the ejector device of the injection molding machine described in Patent Document 4, the ejector pins are assembled into the mold and inserted into the insert mold, and the proximal end side is fixed to the ejector plate. The distal end side ejector pin is pushed by the proximal end side ejector pin. In order to prevent malfunction of the ejector pin due to nested thermal expansion, the distal end side ejector pin is allowed to move in the direction perpendicular to the axis.

JP-A-5-245847 JP 2000-301580 A JP 2007-98957 A JP 2005-254514 A

  In the ejector device of the conventional injection molding machine, when changing the mold in the injection molding machine, the ejector pin is arranged to change the arrangement of the ejector pin according to the new mold (mold shape, size, etc.). May need to be replaced. However, the ejector pin is configured as one continuous integrated pin. In the structure in which the base end portion of the ejector pin is fixed to the ejector plate as in Patent Documents 1 and 2, the ejector pin is replaced. The load is large, and the time and cost required to replace the ejector pins are increased.

  That is, in the ejector device described in Patent Document 1, when exchanging the ejector pin, the retainer plate is attached to and detached from the ejector plate. For this purpose, a plurality of bolts are operated, and the ejector pin is attached to the retainer plate from the back side. This requires a cumbersome and heavy work of attaching and detaching.

  In the ejector device described in Patent Document 2, when the ejector pin is replaced, the ejector pin is rotated to fasten / release the base end portion of the ejector pin to / from the ejector plate. In particular, the base end portion of the ejector pin is ejected from the ejector pin. When fastening to the plate, it is necessary to perform an operation with a heavy load, in which the proximal end screw portion of the ejector pin is positioned in the screw hole of the ejector plate, and a large force is required to rotate the ejector pin. At that time, the ejector plate may be damaged.

  In the ejector device described in Patent Document 3, the base end flange portion of the ejector pin is engaged with the concave portion of the joint connected to the air cylinder so as to be disengageable from the direction orthogonal to the axis, and in a state of being prevented from rotating with a bolt. The ejector pin can be replaced by removing this bolt, but when the ejector pin is inserted into the platen, the base end of the ejector pin is moved in the direction perpendicular to the axis, that is, to the joint. It is difficult to perform connection / disconnection, and it is also very unreasonable to provide a plurality of air cylinders including unused air cylinders in order to cope with the change in the arrangement of the ejector pins.

  In the case of medium-sized and large-sized injection molding machines of several hundred t to several hundreds of t class, when exchanging the mold, the arrangement of the ejector pins is often changed, and the exchanging work of the ejector pins is often required. However, the length and thickness of the ejector pin are increased. For example, in an injection molding machine of about 650 t, the ejector pin has a diameter of about 35 to 50 mm and a length of about 1 m, so the weight of the ejector pin is heavy. Become. Therefore, the ejector pin replacement work load becomes very large.

  An object of the present invention is to fix a part or all of each ejector rod to the ejector plate by magnetic force so as to be removable, particularly when exchanging the ejector rod when exchanging the mold in the injection molding machine. It is an object of the present invention to provide an ejector device for an injection molding machine that can reduce the replacement work load of the ejector rod and reduce the time and cost required for replacing the ejector rod.

  The invention according to claim 1 is an ejector apparatus for an injection molding machine that ejects a molded product from a mold attached to a platen of an injection molding machine. A plurality of rod insertion holes (pin insertion holes) formed in the platen in a penetrating manner. A plurality of ejector rods (ejector pins) slidably inserted in all or a part of the plurality of rod insertion holes, an ejector plate disposed on the back side of the platen, and the platen Ejector driving means for driving the ejector plate toward and away from the platen, and magnet type rod fixing means for generating magnetic force for removably fixing a part or all of each ejector rod to the ejector plate. It is characterized by that.

  The ejector rod to be used can be configured by mounting a part or all of the necessary ejector rod on the ejector plate based on a mold attached to the platen. When replacing the mold in the injection molding machine, remove some or all of the unnecessary ejector rods from the mold fixing surface side of the platen according to the new mold, and newly The ejector plate can be exchanged by attaching a part or all of the ejector rod to the ejector plate.

  As a subordinate claim of claim 1, when the magnet type rod fixing means generates a magnetic force for removably fixing a part of each ejector rod to the ejector plate, the following configuration can be adopted.

  The plurality of ejector rods are slidably inserted into all or a part of the plurality of rod insertion holes and have base ends fixed to the ejector plate, and at least a part of the base rods. A plurality of detachable rods that can be attached to and detached from the base rod, and the magnet type rod fixing means attracts the base end portion of each of the detachable rods to the distal end portion of the base rod by a magnetic force. The base end portion of the base rod is screwed to the ejector plate (Claim 3).

  A clamp plate having a plurality of magnet units for attracting the mold by magnetic force is fixed to a mold fixing surface of a platen, and a plurality of plate-side rod insertion holes communicating with the plurality of rod insertion holes respectively are connected to the clamp plate. (Claim 4). When the ejector rod is in the ejected position, the base rod is configured such that the tip of the base rod is located on the platen side with respect to the mold.

  The magnet-type rod fixing means is a plurality of magnets provided at equal intervals in the circumferential direction at the tip end of each base rod, and a plurality of magnets adjacent to each other in the circumferential direction are arranged to be opposite to each other. A plurality of second magnets arranged at equal intervals in the circumferential direction at a base end portion of each detachable rod and a plurality of second magnets arranged so that the magnetic poles of magnets adjacent in the circumferential direction are opposite to each other. And a magnet. The magnet-type rod fixing means causes the base end of the detachable rod to be attracted to the tip of the base rod by matching the circumferential positions of the first and second magnets having opposite magnetic poles. The detachable rod is configured to be removable from the base rod using the repulsive forces of the first and second magnets having the same magnetic pole by rotating with respect to the base rod.

  The magnet type rod fixing means has a magnet provided on at least one of a distal end portion of each base rod and a proximal end portion of the detachable rod, and the proximal end portion of the detachable rod and the distal end portion of the base rod are attracted to each other. From the state, the suction force reducing means for reducing the suction force by rotating the detachable rod with respect to the base rod is provided (claim 8). An engagement hole formed in one central portion of the distal end of each base rod and the proximal end of the detachable rod, and the distal end of each base rod and the proximal end of the detachable rod so as to engage with the engagement hole And an engaging pin made of a non-magnetic material attached to the other central portion of the portion in a protruding manner.

  Further, as a dependent claim of claim 1, the following configuration can be adopted when the magnet type rod fixing means generates a magnetic force for detachably fixing all the ejector rods to the ejector plate.

  The ejector rod is configured as one continuous integral ejector rod, and the magnet type rod fixing means is configured to generate a magnetic force for fixing the integral ejector rod to the ejector plate. And a magnet provided on at least one of the portions of the ejector plate where the integrated ejector rods contact each other (claim 10). An attraction force reducing means is provided for reducing the attraction force by rotating the integrated ejector rod from the state in which the integrated ejector rod and the ejector plate are adsorbed.

  According to the ejector device of the injection molding machine of claim 1, the ejector apparatus includes the plurality of rod insertion holes, the plurality of ejector rods, the ejector plate, and the ejector driving means, and in particular, a part or all of each ejector rod on the ejector plate. Since there is a magnetic rod fixing means that generates magnetic force for removably fixing the plate, it is possible to easily and reliably attach or detach a part or all of each ejector rod to the ejector plate from the mold fixing surface side of the platen. it can. The ejector rod to be used can be configured by mounting a part or all of the necessary ejector rod on the ejector plate based on a mold attached to the platen. Then, when exchanging the mold in the injection molding machine, in accordance with the new mold, remove some or all of the unnecessary ejector rods from the mold fixing surface side of the platen from the ejector plate, and The ejector plate can be easily replaced by attaching a part or all of the ejector rod necessary for the ejector plate to the ejector plate. In other words, the ejector rod replacement work load can be reduced, and therefore the time and cost required to replace the ejector rod can be reduced.

  According to the ejector device of the injection molding machine of claim 2, the plurality of ejector rods are slidably inserted into all or a part of the plurality of rod insertion holes, and the base end portions are fixed to the ejector plate. The base rod and a plurality of detachable rods that can be attached to and detached from at least some of the base rods. The magnetic rod fixing means uses a magnetic force at the base end of each detachable rod at the tip of the base rod. When the mold is exchanged in the injection molding machine, the plurality of base rods are fixed in advance to the ejector plate in an arrangement based on a plurality of types of molds scheduled to be used in the injection molding machine. Depending on the new mold, remove the unnecessary detachable rod from the base rod from the mold fixing surface side of the platen, and remove the newly required detachable rod from the base rod. It is possible to easily replace the detachable rod so that it is attached. At that time, it is only necessary to replace the detachable rod, not the entire ejector rod including the base rod, thus further reducing the replacement work load of the ejector rod. be able to.

  According to the ejector device of the injection molding machine of the third aspect, since the base end portion of the base rod is screwed and fastened to the ejector plate, the structure for fixing the base end portion of the base rod to the ejector plate can be simplified. it can.

  According to the ejector device of the injection molding machine of claim 4, a clamp plate having a plurality of magnet units for attracting the mold magnetically is fixed to the mold fixing surface of the platen, and a plurality of rod insertion holes are provided in the clamp plate. Since a plurality of plate-side rod insertion holes communicating with each other are formed, it is possible to easily and reliably attach and remove the mold to and from the platen. Play.

  According to the ejector device of the injection molding machine of claim 5, since the tip end portion of the base rod is positioned on the platen side with respect to the mold when the ejector rod is in the ejected position, the base is not used. It is possible to prevent malfunction of the rod due to interference with the mold.

  According to the ejector device of the injection molding machine of claim 6, the magnet type rod fixing means is a plurality of magnets provided at equal intervals in the circumferential direction at the tip of each base rod, and adjacent magnets in the circumferential direction. Magnetic poles of a plurality of first magnets arranged so that their magnetic poles are opposite to each other and a plurality of magnets provided at equal intervals in the circumferential direction at the base end of each detachable rod Since the plurality of second magnets arranged so as to be opposite to each other are provided, when the detachable rod is replaced, the detachable rod of the detachable rod is rotated at the rotational position where the circumferential positions of the first and second magnets coincide with each other. By using the repulsive force of the first and second magnets with the same magnetic pole by securely adsorbing the base end to the tip of the base rod and rotating the detachable rod with respect to the base rod A removable rod can be removed easily from the base rod.

  According to the ejector device of the injection molding machine of claim 7, the magnet type fixing means aligns the circumferential positions of the first and second magnets having opposite magnetic poles so that the base end portion of the detachable rod is the tip of the base rod. Since the detachable rod can be removed from the base rod by using the repulsive force of the first and second magnets with the same magnetic pole by rotating the detachable rod with respect to the base rod from this state. The effect similar to that of claim 6 is obtained.

  According to the ejector device of the injection molding machine of claim 8, the magnet type rod fixing means has a magnet provided on at least one of the distal end portion of each base rod and the proximal end portion of the detachable rod. The structure of the magnet type rod fixing means is provided with an attractive force reducing means for reducing the attractive force by rotating the detachable rod with respect to the base rod from the state where the end and the tip of the base rod are adsorbed. The base end portion of the detachable rod can be securely adsorbed to the tip end portion of the base rod, and the detachable rod can be easily detached from the base rod by rotating with respect to the base rod.

  According to the ejector device of the injection molding machine of the ninth aspect, the engagement hole formed in one central portion of the distal end portion of each base rod and the proximal end portion of the detachable rod and the engagement hole are engaged with each other. Provided with an engaging pin made of a non-magnetic material projectingly attached to the other central portion of the base end portion of each base rod and the base end portion of the detachable rod. In addition, since the engaging pin is made of a non-magnetic material, it is possible to suppress the generation of unnecessary attracting force due to magnetic force between the engaging pin, the base rod on the engaging hole side, and one of the detachable rods. The detachable rod can be reliably and smoothly attached to and detached from the base rod from the mold fixing surface side of the platen, and the tip of the base rod and the detachable rod are further engaged by the engagement between the engagement hole and the engagement pin. Can be prevented from breaking and breaking .

  According to the ejector device of the injection molding machine of claim 10, the ejector rod is constituted by one continuous integral ejector rod, and the magnetic rod fixing means is for fixing each integral ejector rod to the ejector plate. In order to generate a magnetic force, the injection molding machine has a magnet provided on at least one of the base end portion of each integral ejector rod and the portion of the ejector plate where each integral ejector rod abuts. When exchanging the mold, remove the unnecessary integral type ejector rod from the ejector plate from the mold fixing surface side of the platen according to the new mold, and replace the new integral type ejector rod with the ejector plate. The integrated ejector rod can be easily replaced to fit the ejector It is possible to reduce the exchange work load of the rod. In addition, since only the necessary integral type ejector rod needs to be mounted on the ejector plate, the load on the ejector driving means can be reduced.

  According to the ejector device of the injection molding machine of claim 11, there is provided an adsorption force reducing means for reducing the adsorption force by rotating the integrated ejector rod from the state where the integrated ejector rod and the ejector plate are adsorbed. Therefore, the integral ejector rod can be easily removed from the ejector plate by rotating the integral ejector rod from the mold fixing surface side of the platen.

  An ejector device of an injection molding machine according to the present invention for ejecting a molded product from a mold attached to a platen of an injection molding machine has a plurality of rod insertion holes formed in a penetrating manner in the platen, all or one of the plurality of rod insertion holes. A plurality of ejector rods that are slidably inserted into the plate, an ejector plate disposed on the back side of the platen, an ejector drive means for driving the ejector plate toward and away from the platen, and an ejector plate A magnet type rod fixing means for generating a magnetic force for removably fixing a part or all of each ejector rod is provided.

  As shown in FIGS. 1 to 3, the injection molding machine 1 includes a pair of opposed platens 2 and 3 (a fixed platen 2 and a movable platen) to which a mold M (a fixed mold M1 and a movable mold M2) is attached. 3) A platen drive mechanism 4 having a hydraulic cylinder (or a drive motor) for driving the movable platen 3 in a direction approaching and separating from the fixed platen 2 in order to clamp and open the mold M, and the movable platen 3 An injection mechanism 6 having four guide rods 5 that are guided and supported movably in the approaching / separating direction, an injection cylinder 6a for supplying a synthetic resin in a molten state to a cavity in the mold M clamped, and a movable metal An ejector device 7 for ejecting a molded product from the mold M2 is provided.

  The fixed mold M1 is fixed to the mold fixing surface 2a of the fixed platen 2 by a plurality of mechanical clamp devices (not shown). Similarly, the movable mold M2 is fixed to the mold fixing surface 3a of the movable platen 3. It is fixed by a mechanical clamp device (not shown). A plurality of types of molds having different sizes and shapes can be attached to and detached from the mold fixing surfaces 2a and 3a.

  When injection molding is performed by the injection molding machine 1, the movable platen 3 is driven in the direction approaching the fixed platen 2 by the platen drive mechanism 4, and the movable mold M2 is pressed against the fixed mold M1 as shown in FIG. In this state, a molten synthetic resin is supplied from the tip of the injection cylinder 6a to the cavity in the mold M to mold a molded product. Thereafter, the platen drive mechanism 4 drives the movable platen 3 away from the fixed platen 2, and as shown in FIG. 2, the movable mold M2 is separated from the fixed mold M1 to be in the mold open state. The ejector device 7 ejects the molded product from the movable mold M2.

The ejector device 7 will be described in detail.
In addition, it demonstrates suitably from the left-right direction shown by the arrow in FIG. 1 as the left-right direction.

  As shown in FIGS. 1 to 9, the ejector device 7 includes a plurality of (for example, 13) rod insertion holes 10 formed in the movable platen 3 so as to penetrate in the left-right direction, and all of the plurality of rod insertion holes 10. A plurality of (for example, 13) ejector rods 11 that are slidably inserted in the left and right directions, an ejector plate 12 disposed on the back side (left side) of the movable platen 3, and the movable platen 3. An ejector drive mechanism 13 that drives the ejector plate 12 in the left-right direction approaching and moving away from the movable platen 3 and a magnetic force for removably fixing the ejector rod 16 that is a part of each ejector rod 11 to the ejector plate 12 are generated. And a magnet type rod fixing mechanism 14 to be operated.

  The number and arrangement of the plurality of rod insertion holes 10, the diameter of each rod insertion hole 10, the number and arrangement of the plurality of ejector rods 11, the length and diameter of each ejector rod 11, the size of the ejector plate 12, etc. 1 is set based on a plurality of types of molds scheduled to be used. The ejector drive mechanism 13 has a fluid pressure cylinder 13a. The ejector driving mechanism 13 drives the ejector plate 12 in the left-right direction with respect to the movable platen 3, so that the ejector pin 11 has advanced (see FIG. 2) and the retracted standby position (see FIG. 1). It is driven back and forth.

  The plurality of ejector rods 11 are made of a plurality of (for example, 13) magnetic bodies (for example, made of steel) that are slidably inserted into all of the plurality of rod insertion holes 10 and whose base ends are fixed to the ejector plate 12. ) And a plurality of magnetic body (for example, steel) detachable rods 16 that can be attached to and detached from at least some of the base rods 15. When the ejector rod 11 is in the eject position, the tip of the base rod 15 is configured to be positioned closer to the movable platen 3 (left side) than the movable mold M2 (see FIG. 2).

  As shown in FIG. 4, a screw shaft 15 b having a smaller diameter than the rod body 15 a of the base rod 15 is formed at the base end portion (left end portion) of each base rod 15, and this screw shaft 15 b is formed on the ejector plate 12. The base end of the base rod 15 is screwed and fastened to the ejector plate 12 when the step 15c at the boundary between the rod body 15a and the screw shaft 15b is pressed against the ejector plate 12. Has been. In order to rotate the base rod 15, a pair of smooth engaging surfaces 15d with which a tool such as a wrench is engaged is formed on the outer peripheral portion on the proximal end side of the rod body 15a.

  The plurality of detachable rods 16 are provided so as to have a number and a length based on a plurality of types of molds scheduled to be used in the injection molding machine 1. For example, one or a plurality of detachable rods 16 having different lengths are provided for each rod insertion hole 10. However, for a plurality of detachable rods 16 having the same diameter, the number of detachable rods 16 can be reduced by using one detachable rod 16 having the same diameter.

  As shown in FIGS. 4 to 9, the magnet type rod fixing mechanism 14 attracts the base end portion (left end portion) of each detachable rod 16 to the tip end portion (right end portion) of the base rod 15 by magnetic force. A plurality (for example, four) of first magnets 20 provided at the distal end portion of each base rod 15, and a plurality of (for example, four) second magnets 21 provided at the base end portion of each detachable rod 16 It has. The distal end surface 15e of the base rod 15 and the proximal end surface 16a of the detachable rod 16 are both formed as a vertical smooth surface, and these surfaces 15e, 16a come into contact with each other and are fixed in a stable state by the magnetic force. For example, the magnets 20 and 21 are neodymium magnets.

  The plurality of first magnets 20 are arranged at the tip end of the base rod 15 at regular intervals (for example, at intervals of 90 degrees) in the circumferential direction on the radially outer side of the central portion, and the magnetic poles of the magnets 20 adjacent in the circumferential direction. Are arranged so as to be opposite to each other. Each first magnet 20 is formed in a round shaft shape having a short length and a diameter of about ¼ of the diameter of the base rod 15. The plurality of first magnets 20 are fitted and fixed in magnet mounting holes 15f formed in the base rod 15 such that the front end surfaces thereof face the front end surface 15e of the base rod 15.

  Similarly, the plurality of second magnets 21 are adjacent to the proximal end portion of the detachable rod 16 at equal intervals (for example, at intervals of 90 degrees) in the circumferential direction on the radially outer side of the central portion thereof and in the circumferential direction. It arrange | positions so that the magnetic pole of the magnet 21 may turn right and left. Each of the second magnets 21 is formed in a round shaft shape having a short length and a diameter that is about 1/4 of the diameter of the detachable rod 16. The plurality of second magnets 21 are fitted and fixed in magnet mounting holes 16b formed in the detachable rod 16 so that their base end faces the base end surface 16a of the detachable rod 16.

  Then, the magnet type fixing mechanism 14 is provided with a plurality of first and second magnets 20 and 21, so that the circumferential positions of the first and second magnets 20 and 21 having opposite magnetic poles as shown in FIG. , The base end portion of the detachable rod 16 is attracted to the distal end portion of the base rod 15, and from this state, the detachable rod 16 is rotated with respect to the base rod 15 so that the first and second magnets have the same magnetic pole. The detachable rod 16 is configured to be detachable from the base rod 15 by utilizing the repulsive force 20 and 21.

  That is, as shown in FIG. 8, with the first and second magnets 20 and 21 adjacent in the circumferential direction in a state where the circumferential positions of the first and second magnets 20 and 21 having opposite magnetic poles coincide with each other, The magnetic path becomes a magnetic path indicated by an arrow in FIG. When the detachable rod 16 is rotated 90 degrees from this state, the magnetic path by the first and second magnets 20 and 21 becomes the magnetic path shown in FIG.

  An engagement hole 25 is formed in the central portion of the base end portion of each detachable rod 16, and the non-magnetic material (for example, the center portion of the distal end portion of each base rod 15 is engaged with the engagement hole 25. (Made of stainless steel) is fixedly attached to the right protruding shape. The engagement pin 26 is fitted and fixed to a pin mounting recess 15g formed in the base rod 15 at a base end side portion thereof. Therefore, the bolt 27 is inserted into the stepped hole 26a formed in the engaging pin 26, and the bolt 27 is screwed and fastened to the base rod 15 with the head portion engaging the stepped portion of the stepped hole 26a. Has been. A tapered portion 26 b is formed on the outer peripheral portion of the distal end of the engagement pin 26 so that the engagement pin 26 can be smoothly inserted into the engagement hole 25.

The operation and effect of the ejector device 7 of the injection molding machine 1 described above will be described.
The ejector device 7 includes a plurality of rod insertion holes 10, a plurality of ejector rods 11, an ejector plate 12, and an ejector drive mechanism 13, and in particular, a removable rod 16 that is a part of each ejector rod 11 is removed from the ejector plate 12. Since the magnet type rod fixing mechanism 14 for generating a magnetic force for fixing is provided, the detachable rod 16 of each ejector rod 11 can be easily and securely attached to the ejector plate 12 from the mold fixing surface 3a side of the movable platen 3. can do.

  Here, the plurality of ejector rods 11 are slidably inserted into all of the plurality of rod insertion holes 10 and have a base end portion fixed to the ejector plate 12, and at least of the base rods 15. A plurality of detachable rods 16 that can be attached to and detached from some of the base rods 15, and the magnet type rod fixing mechanism 14 attracts the base end portion of each detachable rod 16 to the distal end portion of the base rod 15 by magnetic force. is there. That is, the ejector rod 11 to be used can be configured by mounting the necessary detachable rod 16 on the base rod 15 based on a mold attached to the movable platen 3.

  Therefore, the molds are exchanged in the injection molding machine 1 by fixing the plurality of base rods 15 to the ejector plate 12 in advance in an arrangement based on a plurality of types of molds scheduled to be used in the injection molding machine 1. At this time, in accordance with a new mold, an unnecessary mounting / dismounting rod 16 is removed from the base rod 15 from the mold fixing surface 3a side of the movable platen 3, and a new mounting / dismounting rod 16 is newly mounted on the base rod 15. Thus, the ejector rod 11 (detachable rod 16) can be easily replaced. At this time, not the entire ejector rod 11 including the base rod 15, but only the removable rod 16 may be replaced. That is, the replacement work load of the ejector rod 11 can be greatly reduced, and therefore the time and cost required for replacement of the ejector rod 11 can be greatly reduced.

  Since the base end portion of the base rod 15 is screwed and fastened to the ejector plate 12, the structure for fixing the base end portion of the base rod 15 to the ejector plate 12 can be simplified. Since the tip end of the base rod 15 is positioned closer to the movable platen 3 than the movable mold M2 when the ejector rod 11 is in the ejected position, the unused base rod 15 and the movable mold 3 It is possible to prevent malfunction due to interference.

  The magnet-type rod fixing mechanism 14 is a plurality of magnets 20 provided at equal intervals in the circumferential direction at the distal ends of the base rods 15 so that the magnetic poles of the magnets 20 adjacent in the circumferential direction are opposite to each other. The plurality of first magnets 20 and the plurality of magnets 21 provided at equal intervals in the circumferential direction at the base end portion of each detachable rod 16 so that the magnetic poles of the magnets 21 adjacent in the circumferential direction are opposite to each other. A plurality of second magnets 21 arranged are provided.

  Therefore, the magnet-type fixing mechanism 14 causes the proximal end portion of the detachable rod 16 to be attracted to the distal end portion of the base rod 15 by matching the circumferential positions of the first and second magnets 20 and 21 having opposite magnetic poles. The detachable rod 16 is configured to be removable from the base rod 15 by rotating the detachable rod 16 with respect to the base rod 15 by using the repulsive force of the first and second magnets 20 and 21 having the same magnetic pole. be able to.

  In other words, when the detachable rod 16 is replaced, the base end portion of the detachable rod 16 is securely attached to the distal end portion of the base rod 15 at the rotational position of the detachable rod 16 where the circumferential positions of the first and second magnets 20, 21 coincide. The removable rod 16 can be easily detached from the base rod 15 by using the repulsive force of the first and second magnets 20 and 21 having the same magnetic pole by rotating the removable rod 16 with respect to the base rod 15. Can be removed.

  An engagement hole 25 formed in the central portion of the distal end portion of each base rod 15, and is attached to the other central portion of the base end portion of each detachable rod 16 so as to engage with the engagement hole 25. In addition, since the engaging pin 26 is made of a non-magnetic material due to the positioning function of the engaging hole 25 and the engaging pin 26, the engaging pin 26 is provided. Since an unnecessary attracting force due to a magnetic force can be suppressed between the detachable rod 16 and the detachable rod 16, the detachable rod 16 is reliably and smoothly attached to the base rod 15 from the mold fixing surface 3 a side of the movable platen 3. Further, it is possible to prevent the distal end portion of the base rod 15 and the proximal end portion of the removable rod 16 from being broken and broken by the engagement between the engagement hole 25 and the engagement pin 26.

  Next, Examples 2 to 4 will be described. However, substantially the same components as those in the first embodiment are denoted by the same reference numerals, and only different components will be described.

  The ejector device 7A of the second embodiment is obtained by changing the magnet type rod fixing mechanism 14 of the first embodiment. As shown in FIGS. 10 to 14, the magnet type rod fixing mechanism 14 </ b> A is provided at the base end portion of the ring-shaped first magnet 30 provided at the distal end portion of each base rod 15 and the detachable rod 16. The ring-shaped second magnet 31 is provided, and the attaching force is increased by rotating the attaching / detaching rod 16 relative to the base rod 15 from the state in which the base end portion of the attaching / detaching rod 16 and the tip end portion of the base rod 15 are attracted. An adsorbing force lowering mechanism 35 for lowering is provided. For example, the magnets 30 and 31 are neodymium magnets.

  The first and second magnets 30 and 31 have the same shape, and the inner diameter thereof is substantially the same as the diameter of the engagement pin 25. The first magnet 30 is fitted and fixed in a magnet mounting hole 15 h formed in the base rod 15 so that the front end surface of the first magnet 30 faces the front end surface 15 e of the base rod 15 in a state where the first magnet 30 is externally fitted to the engagement pin 25. ing. The second magnet 31 is fitted into a magnet mounting hole 16c formed in the detachable rod 16 so that the base end surface thereof faces the base end surface 16a of the detachable rod 16 and the first magnet 30 and the magnetic pole are reversed. The inner peripheral surface of the engagement hole 25 constitutes a part of the inner peripheral surface.

  The attracting force lowering mechanism 35 has a tapered groove 36 formed in an arc shape centered on the axis of the base rod 15 and a protruding shape at the base end of the detachable rod 16 so as to be engageable with the tapered groove 36. And an engaging pin 37 attached to the. The tapered groove 36 is provided with a relatively short length on the outer side in the radial direction of the first magnet 30. At one end in the circumferential direction of the taper groove 36, the taper surface 36 a of the taper groove 36 continues to the tip surface 15 e of the base rod 15, and a step 36 b is formed at the other circumferential end of the taper groove 36.

  In this attraction force reducing mechanism 35, the engagement pin 37 is accommodated near the stepped portion 36 b of the tapered groove 36 to bring the distal end surface 15 e of the base rod 15 and the proximal end surface 16 a of the detachable rod 16 into contact with each other. It can be reliably attracted by the magnetic force of the second magnets 30 and 31. From this state, when the detachable rod 16 is rotated in a direction in which the engagement pin 37 is separated from the stepped portion 36b, the engagement pin 37 engages with the tapered surface 36a, and the rotational force of the detachable rod 16 is increased. It is converted into a force in a direction to separate 16 from the base rod 15. That is, by rotating the detachable rod 16, it can be separated from the base rod 15 and the adsorption force can be reduced.

  When attaching the proximal end portion of the detachable rod 16 to the distal end portion of the base rod 15, if the engaging pin 37 contacts the distal end surface 15 e of the base rod 15, the detachable rod 16 is rotated from there to The pin 37 can be accommodated in the vicinity of the stepped portion 36b of the tapered groove 36 so that the distal end surface 15e of the base rod 15 and the proximal end surface 16a of the detachable rod 16 can be brought into contact with each other. In this case, by rotating the detachable rod 16 in the direction opposite to the direction in which the adsorption force is reduced, the engagement pin 37 engages with the stepped portion 36b. Thus, it can be confirmed that the distal end surface 15e of the base rod 15 and the proximal end surface 16a of the detachable rod 16 are in contact with each other.

  According to the ejector device 7A, the magnet type rod fixing mechanism 14A has the first and second magnets 30 and 31 provided at both the distal end portion of each base rod 15 and the proximal end portion of the detachable rod 16. This is provided with an adsorption force reducing mechanism 35 for reducing the adsorption force by rotating the attachment / detachment rod 16 with respect to the base rod 15 from the state where the proximal end portion of the attachment / detachment rod 16 and the tip end portion of the base rod 15 are adsorbed. Thus, by simplifying the structure of the magnet type rod fixing mechanism 14A, the base end portion of the detachable rod 16 is surely attracted to the distal end portion of the base rod 15, and the detachable rod 16 is rotated with respect to the base rod 15. Can be easily removed from the base rod 15.

  The ejector device 7B of the third embodiment is obtained by changing the ejector rod 11 and the magnet type rod fixing mechanism 14 of the first embodiment. As shown in FIGS. 15 and 16, each of the plurality of ejector rods 11 </ b> B is configured as one continuous ejector rod 11 </ b> B made of a magnetic material (for example, steel), and includes a plurality of rod insertion holes 10. All or a part is slidably inserted. The ejector plate 12 is also made of a magnetic material (for example, steel).

  In order to generate a magnetic force for fixing each integrated ejector rod 11B to the ejector plate 12, the magnet type rod fixing mechanism 14B is provided in a plurality (for example, a portion of the ejector plate where the integrated ejector rod abuts. 4) first magnets 40, and a plurality of (for example, 4) second magnets 41 provided at the base end of each integrated ejector rod 11B, and the integrated ejector rod 11B and ejector plate. 12 is provided with a suction force lowering mechanism 35B that lowers the suction force by rotating the integrated ejector rod 11B from the state where the head 12 is sucked. For example, the magnets 40 and 41 are neodymium magnets.

  Basically, the plurality of first magnets 40 are attached to the ejector plate 12 in the same manner as the structure in which the plurality of first magnets 20 of the first embodiment are attached to the distal end portion of the base rod 15. A plurality of second magnets 41 are attached to the proximal end portion of the integrated ejector rod 11B basically in the same manner as the structure in which the magnet 30 is attached to the proximal end portion of the detachable rod 16.

  Therefore, the magnet type rod fixing mechanism 13B causes the base end portion of the integrated ejector rod 11B to be attracted to the ejector plate 12 by matching the circumferential positions of the first and second magnets 40, 41 having opposite magnetic poles. The integrated ejector rod 11B is removed from the ejector plate 12 using the repulsive force of the first and second magnets 40 and 41 having the same magnetic pole by rotating the integrated ejector rod 11B relative to the ejector plate 12 from the state. Thus, the adsorption force reduction mechanism 35B is configured.

  Further, an engagement hole 45 is formed in the central portion of the base end portion of each integrated ejector rod 11B, and the ejector plate 12 is made of a non-magnetic material (for example, made of stainless steel) so as to engage with the engagement hole 45. ) Is fixedly attached to the right protruding shape. The engaging pin 46 is attached to the ejector plate 12 with a structure basically similar to the structure in which the engaging pin 26 of the first embodiment is attached to the tip of the base rod 15.

  According to this ejector apparatus 7B, when exchanging the mold in the injection molding machine 1, an unnecessary integral type ejector rod 11B is attached from the mold fixing surface 3a side of the movable platen 3 according to a new mold. The integrated ejector rod 11B can be easily replaced so that it can be removed from the ejector plate 12 and a new integral ejector rod 11B can be attached to the ejector plate 12, thereby reducing the replacement work load of the ejector rod 11B. can do. Moreover, since only the necessary integral ejector rod 11B needs to be attached to the ejector plate 12, the load on the ejector drive mechanism 4 can be reduced.

  In addition, since the integrated ejector rod 11B and the ejector plate 12 are adsorbed, the integrated ejector rod 11B is provided with an adsorption force reducing mechanism 35B that reduces the attractive force. The integrated ejector rod 11B can be easily and reliably removed from the ejector plate 12 by rotating the integrated ejector rod 11B from the fixed surface 3a side.

  As shown in FIGS. 17 and 18, the injection molding machine 1 </ b> C according to the fourth embodiment includes a magnetic fixing device 50 that fixes the fixed mold M <b> 1 to the fixed platen 2, and a magnetic force that fixes the movable mold M <b> 2 to the movable platen 3. Type fixing device 60. The magnetic fixing device 50 on the fixed platen 2 side includes a clamp plate 51 fixed to the mold fixing surface 2a of the fixed platen 2, and a plurality of magnet units (not shown) incorporated in the clamp plate 51. The fixed mold M1 is attracted to the clamp plate 51 by the magnetic force generated by the plurality of magnet units.

  The magnetic fixing device 60 on the movable platen 3 side includes a clamp plate 61 fixed to the mold fixing surface 3 a of the movable platen 3, and a plurality of magnet units 62 incorporated in the clamp plate 61. The movable mold M <b> 2 is attracted to the clamp plate 61 by the magnetic force generated by the unit 62. The basic configuration of the magnetic fixing devices 50 and 60 is the same as that described in, for example, Japanese Patent Application Laid-Open No. 2008-200927 filed by the applicant of the present application, and a description thereof will be omitted.

  The ejector device 7C is a modification of the ejector rod 11 of the first embodiment, and further includes a plurality of plate-side rod insertion holes 65 formed in the clamp plate 61 so as to communicate with the plurality of rod insertion holes 10, respectively. is there. A plurality of magnet units 62 are provided, for example, in the arrangement shown in FIG. 18 so as not to interfere with the plurality of plate-side rod insertion holes 65. The ejector rod 11C includes a plurality of base rods 15 similar to those of the first embodiment and a plurality of detachable rods 16C having a length longer than that of the detachable rod 16 of the first embodiment.

  According to the ejector device 7C, the clamp plate 61 having a plurality of magnet units 62 for attracting the movable mold M2 by magnetic force is fixed to the mold fixing surface 3a of the movable platen 3, and a plurality of rods are attached to the clamp plate 61. Since the plurality of plate-side rod insertion holes 65 respectively communicating with the insertion holes 10 are formed, the movable mold M2 can be easily attached to and detached from the movable platen 3, so that the embodiment The same effect as that of the ejector device 7 of 1 is produced.

In addition, you may change Examples 1-4 as follows.
(1) In the first, second, and fourth embodiments, the plurality of base rods 15 are slidably inserted into a part of the plurality of rod insertion holes 10, and their base ends are fixed to the ejector plate 12. That is, the plurality of ejector rods 11 and 11B are slidably inserted into a part of the plurality of rod insertion holes 10.

(2) In the first, third, and fourth embodiments, in addition to four, the first magnets 20 and 40 such as two or six are provided at the tip of each base rod 15. , 40 are formed in an appropriate shape and size, arranged at equal intervals with an appropriate interval in the circumferential direction, and arranged so that the magnetic poles of the adjacent magnets 20, 40 are opposite to each other in the circumferential direction. The Similarly, the number of second magnets 21 and 41 such as two or six other than four is provided at the tip of each of the detachable rods 16 and 16C, and the second magnets 21 and 41 have an appropriate shape and The magnetic poles of the magnets 21 and 41 adjacent to each other in the circumferential direction are arranged so as to be opposite to each other at equal intervals with an appropriate interval in the circumferential direction.

(3) In Example 2, the 1st magnet 30 provided in the front-end | tip part of each base rod 15 or the 2nd magnet 31 provided in the base end part of the attachment / detachment rod 16 is abbreviate | omitted. That is, the magnet type fixing mechanism 14 </ b> A includes the magnets 30 or 31 provided only on one of the distal end portion of each base rod 15 and the proximal end portion of the detachable rod 16.

(4) In the third and fourth embodiments, the magnet type fixing mechanism 14A of the second embodiment is employed, and further, the attraction force reducing mechanism 35 of the second embodiment is employed. In this case, you may abbreviate | omit the 1st magnet 30 provided in the front-end | tip part of each base rod 15, or the 2nd magnet 31 provided in the base end part of the detachable rods 16 and 16C.

(5) In the first to fourth embodiments, the ejector drive mechanism 13 can employ a drive motor as a drive source in addition to the fluid pressure cylinder. By such an actuator, the ejector plate 12 can be connected via a toggle mechanism or a ball screw mechanism. Various ejector drive mechanisms, such as driving the motor, can be employed.
(6) In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

It is a front view of the injection molding machine which has the ejector apparatus of Example 1, and a metal mold | die (mold closing state). It is a front view of the principal part of an injection molding machine and a metal mold | die (mold opening state). It is the III-III sectional view taken on the line of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a perspective view of the front end side part of a base rod. It is a perspective view of the base end side part of a detachable rod. It is the VII-VII sectional view taken on the line of FIG. It is the VIII-VIII sectional view taken on the line of FIG. 7 which shows the adsorption | suction state of a base rod and a detachable rod. FIG. 9 is a view corresponding to FIG. 8 illustrating a non-adsorption state of the base rod and the detachable rod. FIG. 5 is a diagram corresponding to FIG. 4 of the second embodiment. It is a perspective view of the front end side part of a base rod. It is a perspective view of the base end side part of a detachable rod. It is sectional drawing of an adsorption power fall mechanism. It is sectional drawing of an adsorption power fall mechanism. FIG. 6 is a front view of an injection molding machine having an ejector device of Example 3 and a mold. It is the XVI-XVI sectional view taken on the line of FIG. FIG. 6 is a front view of an injection molding machine having an ejector device of Example 4 and a mold. It is the XVIII-XVIII sectional view taken on the line of FIG.

Explanation of symbols

M2 Movable mold 1 Injection molding machine 3 Movable platen 3a Mold fixed surface 7, 7A, 7B, 7C Ejector device 10 Rod insertion hole 11, 11C Ejector rod 11B Ejector rod 12 Ejector plate 13 Ejector drive mechanism 14, 14A, 14B Magnet type rod fixing mechanism 15 Base rods 16, 16C Removable rods 20, 30, 40 First magnets 21, 31, 41 Second magnets 25, 45 Engaging holes 26, 46 Engaging pins 35, 35B Adsorption force reducing mechanism 61 Clamp plate 62 Magnet unit 65 Plate side rod insertion hole

Claims (11)

In an ejector device of an injection molding machine for ejecting a molded product from a mold attached to a platen of an injection molding machine,
A plurality of rod insertion holes formed in the platen in a penetrating manner;
A plurality of ejector rods slidably inserted through all or a part of the plurality of rod insertion holes;
An ejector plate disposed on the back side of the platen;
Ejector driving means for driving the ejector plate toward and away from the platen with respect to the platen;
A magnet type rod fixing means for generating a magnetic force for removably fixing a part or all of each ejector rod to the ejector plate;
An ejector device for an injection molding machine. The plurality of ejector rods are slidably inserted into all or a part of the plurality of rod insertion holes and have base ends fixed to the ejector plate, and at least a part of the base rods. A plurality of detachable rods that can be attached to and detached from the base rod;
The ejector device for an injection molding machine according to claim 1, wherein the magnet type rod fixing means attracts the base end portion of each detachable rod to the tip end portion of the base rod by a magnetic force.   The ejector device for an injection molding machine according to claim 2, wherein a base end portion of the base rod is screwed and fastened to an ejector plate.   A clamp plate having a plurality of magnet units for attracting the mold by magnetic force is fixed to a mold fixing surface of a platen, and a plurality of plate-side rod insertion holes communicating with the plurality of rod insertion holes respectively are connected to the clamp plate. 3. The ejector device for an injection molding machine according to claim 2, wherein the ejector device is formed.   3. The ejector device for an injection molding machine according to claim 2, wherein when the ejector rod is in the ejected position, the tip of the base rod is positioned on the platen side with respect to the mold.   The magnet-type rod fixing means is a plurality of magnets provided at equal intervals in the circumferential direction at the tip end of each base rod, and a plurality of magnets adjacent to each other in the circumferential direction are arranged to be opposite to each other. A plurality of second magnets arranged at equal intervals in the circumferential direction at a base end portion of each detachable rod and a plurality of second magnets arranged so that the magnetic poles of magnets adjacent in the circumferential direction are opposite to each other. The ejector device for an injection molding machine according to claim 2, further comprising a magnet.   The magnet-type rod fixing means causes the base end of the detachable rod to be attracted to the tip of the base rod by matching the circumferential positions of the first and second magnets having opposite magnetic poles. 7. The injection molding according to claim 6, wherein the removable rod is configured to be removable from the base rod by utilizing the repulsive force of the first and second magnets having the same magnetic pole by rotating with respect to the base rod. Ejector device of the machine. The magnet type rod fixing means has a magnet provided on at least one of a distal end portion of each base rod and a proximal end portion of the detachable rod,
An adsorption force reducing means for reducing the adsorption force by rotating the attachment / detachment rod with respect to the base rod from a state in which the proximal end portion of the attachment / detachment rod and the distal end portion of the base rod are adsorbed is provided. The ejector apparatus of the injection molding machine of Claim 2.   An engagement hole formed in one central portion of the distal end of each base rod and the proximal end of the detachable rod, and the distal end of each base rod and the proximal end of the detachable rod so as to engage with the engagement hole The ejector device for an injection molding machine according to any one of claims 6 to 8, further comprising an engagement pin made of a non-magnetic material attached to the other central portion of the portion in a protruding manner. The ejector rod is configured as a single continuous integral ejector rod;
In order to generate a magnetic force for fixing each integrated ejector rod to the ejector plate, the magnet type rod fixing means includes a base end portion of each integrated ejector rod and each integrated ejector rod of the ejector plate. The ejector device for an injection molding machine according to claim 1, further comprising a magnet provided on at least one of the abutting portions.   11. The injection molding according to claim 10, further comprising an adsorption force reducing means for reducing the adsorption force by rotating the integral ejector rod from a state in which the integral ejector rod and the ejector plate are adsorbed. Ejector device of the machine.